Sp4 problem, fonts resized

Hello,
a user here at work has installed SP4 for W2K and now he
has problems with the computer. The fonts have been
resized in windows where you can't change them, everything
in outlook was bold, excel was in italic. Most of it got
back to normal after a couple of reboots, but he still has
problems with some windows beeing almost useless because
he can't read in them.
Any ideas?
Thanks/Maria